This project represents a multidisciplinary approach to the study and treatment of the severely traumatized patient. Sophisticated engineering methodology including a dedicated on-site digital computer which permits data logging of multiple analog voltages in real time. Patients are instrumented for measurement of respiratory gas flow using a bag box wedge spirometer assembly, respiratory gas measurements using a mass spectrometer, cardiac outputs using cardiogreen dye and the usual pressure transducers for measuring transpulmonary, central venous, left atrial and arterial pressure. Analog voltages from these devices are analyzed in the computer permitting immediate computation of tidal volume, functional residual capacity, static and dynamic pulmonary compliance, oxygen consumption, carbon dioxide output, cardiac output and various measurements of renal function. Studies to date have demonstrated the marked changes in functional residual capacity in association with the post traumatic respiratory distress syndrome and a method of therapy has been delineated. Plans for the next year include enlargement of the system to include multiple patients from multiple input terminals and extension of the studies on renal function and the beginning of investigations of alterations in cerebral function.